Return-flue boiler.



No. '795,406- v PATENTED JULY 25, 1905.

W. MORAN.

RETURN PLUE BOILER.

APPLICATION FILED SEPT. 20.1904.

2 SHEETS-SHEET l.

s' digg/ffii; War/reg@- Q yggw MAb/LW ma PATENTED JULY 25. 1905.

W. MORAN. RETURN FLUB BOILER.

APPLICATION FILED SEPT. 20, 1904.

2 SHEETS-SHEET 2.

UNITED STATES PATENT OFFICE.

RETURN-FLUE BOILER.

Specification of Letters Patent.

Patented July 25, 1905.

Application iiled September 20, 1904. Serial No. 225,214.

T 0 all whom, it' may concern:

Be it known that I, WILLIAM MoRAN, a citizen of the United States, residing at Hopkins, in the county of Hennepin and State of Minnesota, have invented certain new and useful Improvements in Return-Flue Boilers; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

My invention relates to return-Hue boilers, and has for its object to improve the same in the several particulars hereinafter noted.

The invention consists of the novel devices and combinations of devices hereinafter described, and defined in the claims.

In the accompanying drawings, which illustrate my invention, like characters indicate litke parts throughout the several views.

Figure l is a vertical section taken centrally through a horizontal boiler from front to rear designed in accordance with my invention. Fig. 2 is a transverse vertical section taken on the line 062 az? of Fig. l, and Fig. 3 is a transverse vertical section taken on the line :r3 :r3 of Fig. l.

The numeral 1 indicates a horizontally-disposed and preferably cylindrical sheet-iron shell, which at its ends is formed with depending transversely-expanded leg-sections 2 and 3. The leg-section 2 is divided into two compartments et and 5 by a vertically and transversely disposed partition-plate or flue-sheet 6, that extends to the top of the cylindrical shell 1 and cuts off from the main chamber 1'L thereof the forward end portion 1b of said shell. In a similar manner the vertically and transversely extended partitionplate or through-sheet 7 divides the leg 3 into compartments 8 and 9 and extends to the top of the shell l, cutting off from the main chamber of the shell a rear end section 1C. As shown, large hinged doors 10 and ll open, respectively, into the compartments or chambers 4 and 8 to afford ready access to the flues presently to be described.

As shown, the legs 2 and 3 of the boiler rest, respectively, on the cast front-plate 12 of the fire-box 13 and on the rear wall 14 of a brick foundation, which foundation also involves a bridge wall or partition 15.

The numeral 16 indicates the grates of the fire-box, and the numeral 17 indicates a door which opens into the 'lire-box through the front wall 12 in the usual manner.

The numeral 18 indicates the smoke-stack, which opens from the upper section 1b of the chamber 2.

The numeral 19 indicates a manhole-stopper shown as applied to the intermediate upper, portion of the boiler-shell 1.

The numeral 20 indicates a plurality of approximately horizontal but slightly-inclined water-tubes, which extend through the enlarged section or combustion-chamber 13l of the fire-box 13 and through the inner plates of the legs 2 and 3, being, as shown, expanded at their extreme ends to form steamtight joints with said plates. Extending concentrically through each of these relatively large water-tubes 2O is a relatively small flue 2l. The rear ends of these iiues 21 are passed through the flue-sheet or partitionplate 7 and are expanded to form steamtight joints therewith. At their forward ends the flues 21 connect with stub iiues or thimbles 22, which are passed through the Hue-sheet or partition-plate 6 and are expanded to form steam-tight joints therewith. The forward ends of the flues 21 are expanded to form steam-tight joints with inturned angular iianges 23 of the stub flues or thimbles 22. The stub-iiues 22 are of the same diameter as the tubes 20 or slightly larger, so that when they are removed from the fluesheet 6 openings are afforded, through which the said tubes 20 may be passed to remove them from working positions or to place them in working positions.

Below the lower tubes 20 a plurality of relatively large and short flues 24 are passed through the compartment or chamber 9 and at their ends are expanded to form steamtight joints with the flue-sheets 7 and with the inner plate of the leg 3. Above the upper tubes 20 similar flues 25 extend through the said compartment 9 and are expanded at their ends to form steam-tight joints with the flue-sheet 7 and with the inner plate of the leg 3.

The fire-pot space, including the expanded portion 13a thereof, may be treated as the primary combustion-chamber, and the chamber or compartment S of the leg 3 may be treated as the secondary combustionchamber. The chamber 4, including the space marked 1b, constitutes what is usually designated as the smoke-box. The

The

said chambers or compartments 5 and 9 and the annular passages formed within the tubes 2O outside of the flues 21 will always be filled with water, while the shell-chamber 1l will of course be partly filled with water, so as to leave space for steam at the top thereof. The fines 21 and stub-[lues 22 constitute the return-'dues of the boiler.

T he arrows marked on Fig. l indicate the lines of travel of the [lame and products of combustion, and by reference thereto it will be noted that the llames pass first from. the lire-box proper, 1.3, between and around the tubes 2() and up into the expanded portion 13 of the primary combustion-chamber. The part of the flame or products of combustion will pass upward and through the flues 25 into the secondary combustion-chamber 8, while a part thereof will be drawn downward and will pass through the llues 24 into the lower portion of said secondary com bustion-chamber. From the secondaryT combustion-chamber the flames or products of combustion are drawn through the return- Vdues 2l 22 into the smoke-box 4; and from t'hence out through the smoke-stack 18.

lt will be seen that the flames or products of combustion are caused to twice act upon the water contained in the tubes 2() and are caused to act upon both sides of the columns of water contained in the compartments 5 and fr) and are caused to act upon the end portions as well as the lower portion of the body of water contained within the shell-com partment 1. lt is therefore obvious that with this arrangement an exceedingly large amount of heat-rmliating surface is exposed to the water, from which it results that a boiler of high elliciency is provided. As also evident,

a boiler is provided in which easy access may be had to the flues for the purposes of repair or replacing of llues.

From what has been said it will be understood that the boiler described is capable of modification within the scope of my invention as herein set forth and claimed. Many of the novel features of construction may be incorporated into a vertical boiler without departing from the spirit of my invention.

Vhat l claim, and desire to secure by Letters Patent of the United States, is as follows:

1, In a return-flue boiler having approximately parallel water-legs and a plurality of water-tubes connecting said legs, a primary combustion-chamber, located between said water-legs, a secondary combustion-chamber located outward of one of said water-legs, a smoke-box located outward of the other water-leg, flues passed through one of said water-legs above and below said water-tubes connecting said primary and secondary combustion-chambers, and return-dues passed through said water-tubes and connecting said secondary combustion-chamber with said smoke-box, substantially as described.

2. In a horizontal return-Hue boiler, the combination with a horizontally-extended boiler-body having depending water-legs, of combustion-chamber located between said water-legs, a secondary combustion-chamber located outward of one of said water-legs and extending upward across one end of said boiler-body, a smoke-box located outward of the other water-leg and extending upward across the other end of said boiler-body, flues connecting said primary and secondary combustioli-chambers, water-tubes connecting said water-legs, and return-fines extending through said water tubes and connecting said secondary combustionchamber with said smoke-box, substantially as described.

In testimony whereof I affix my signature in presence of two witnesses.

VVILLIAh/I MORAN.

Vitnesses:

E. WV. JEPPESEN, FRANK D. MERCHANT. 

